package upstream

import (
	"context"
	"testing"

	"cmpp-platform/gateway/internal/queue"
)

func TestConnectionPoolAcquiresAcrossConnections(t *testing.T) {
	pool := &connectionPool{
		conns: []*connection{
			{window: make(chan struct{}, 1)},
			{window: make(chan struct{}, 1)},
		},
	}

	first, releaseFirst := pool.tryAcquireConnection()
	if first == nil {
		t.Fatalf("expected first connection")
	}
	second, releaseSecond := pool.tryAcquireConnection()
	if second == nil {
		t.Fatalf("expected second connection")
	}
	if first == second {
		t.Fatalf("expected pool to use another connection when the first window is full")
	}
	third, _ := pool.tryAcquireConnection()
	if third != nil {
		t.Fatalf("expected nil connection while all windows are full")
	}

	releaseFirst()
	reacquired, releaseReacquired := pool.tryAcquireConnection()
	if reacquired == nil {
		t.Fatalf("expected a connection after releasing a window")
	}
	releaseReacquired()
	releaseSecond()
}

func TestManagerDisconnectChannelRemovesPoolAndStopsReconnects(t *testing.T) {
	pool := &connectionPool{
		channelID:       "channel-1",
		connectionID:    "channel-1:primary",
		config:          normalizeUpstreamConfig(queueUpstreamConfigForTest()),
		reconnectSignal: make(chan struct{}, 1),
		stopCh:          make(chan struct{}),
	}
	manager := &Manager{conns: map[string]*connectionPool{"channel-1": pool}}

	state, err := manager.DisconnectChannel(context.Background(), queue.DisconnectChannelCommand{
		MessageType:  queue.MessageTypeDisconnectChannel,
		ChannelID:    "channel-1",
		ConnectionID: "channel-1:primary",
	})

	if err != nil {
		t.Fatalf("disconnect channel: %v", err)
	}
	if state.Status != "disconnected" || state.CurrentConnections != 0 {
		t.Fatalf("unexpected state: %+v", state)
	}
	if _, exists := manager.conns["channel-1"]; exists {
		t.Fatal("expected channel pool to be removed")
	}
	select {
	case <-pool.stopCh:
	default:
		t.Fatal("expected reconnect supervisor to be stopped")
	}
}

func TestNormalizeUpstreamConfigDefaults(t *testing.T) {
	config := normalizeUpstreamConfig(queueUpstreamConfigForTest())
	if config.DesiredConnections != 1 {
		t.Fatalf("DesiredConnections = %d, want 1", config.DesiredConnections)
	}
	if config.WindowSize != defaultWindowSize {
		t.Fatalf("WindowSize = %d, want %d", config.WindowSize, defaultWindowSize)
	}
	if config.HeartbeatIntervalSeconds != 30 || config.HeartbeatMissThreshold != 3 {
		t.Fatalf("unexpected heartbeat defaults: interval=%d threshold=%d", config.HeartbeatIntervalSeconds, config.HeartbeatMissThreshold)
	}
}

func TestManagerSeparatesConnectionStateAndSupplierEventAPIs(t *testing.T) {
	manager := &Manager{APIBaseURL: "http://main-api/api", EventAPIBaseURL: "http://callback-api/api"}
	pool := manager.newConnectionPool("channel-1", "channel-1:primary", queue.UpstreamConfig{DesiredConnections: 1})
	if pool.apiBaseURL != manager.EventAPIBaseURL {
		t.Fatalf("supplier events must use callback API, got %q", pool.apiBaseURL)
	}
	if manager.APIBaseURL == pool.apiBaseURL {
		t.Fatal("connection-state control API must remain separate from supplier events")
	}
}

func queueUpstreamConfigForTest() queue.UpstreamConfig {
	return queue.UpstreamConfig{
		GatewayHost:    "127.0.0.1",
		GatewayPort:    17890,
		Account:        "account",
		PasswordCipher: "secret",
		CMPPVersion:    "3.0",
	}
}